One cannot hope that an increasing diffusion of the knowledge of the three chief languages will cause these difficulties to diminish, still less to disappear. They will, rather, increase still more, since the number of national languages desiring to take part in the work of civilisation is constantly growing. Already, at the present time, Italian, Spanish, Dutch, and the Scandinavian and Slavonic languages must be taken into account, besides the three chief languages. National sentiment forces the scientific men of these countries to use the national languages, even when they perceive that this procedure does not conduce to mutual understanding. Even if the scientific men themselves were completely free from national _amour propre_, they would be obliged by their fellow-countrymen to employ their own languages, not so much for the purpose of advancing scientific knowledge and learning as in order to contribute by means of their literary and scientific works to the diffusion of their languages and the advancement of their nations. Whoever has observed this phenomenon will be forced to the conclusion that amongst scientific men, at least in Europe, this state of affairs is getting worse rather than better. The increase of the participating languages involves an increase of the periodicals, just at a time when a concentration of the periodical literature is most desirable. The cost of subscriptions, translations, storing, and registration, and the labour and time spent thereon, increase from year to year. Above all, there is a want of translators; ordinary interpreters are not sufficient, since a special knowledge of each subject is required. Where are such persons to be found in sufficient numbers? And how few and far between are those who, when they possess the requisite training, are willing to content themselves with the poorly paid remuneration of a translator! Bad or erroneous translations and faulty abstracts are very harmful; it would be better in such cases that no translation should exist, as then the original would have to be consulted. These difficulties, many more of which could be mentioned, are well known to all scientific men, since each has suffered more or less from them. The question then is, What remedy can we apply? One proposal is to introduce into secondary schools the teaching of modern instead of classical languages, in order to render the students, after matriculation at the universities, capable of taking part in international scientific intercourse. This proposal has arisen from the view that the learning of modern _added_ to that of the classical languages would overburden the secondary schools, whilst the learning of modern languages at the universities would cause equal or greater difficulties.